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<h1 class="title">mainwindow.cpp 示例文件</h1>
<span class="subtitle">touch/fingerpaint/mainwindow.cpp</span>
<!-- $$$touch/fingerpaint/mainwindow.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
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  **     from this software without specific prior written permission.
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  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  <span class="preprocessor">#include &lt;QtWidgets&gt;</span>

  <span class="preprocessor">#include &quot;mainwindow.h&quot;</span>
  <span class="preprocessor">#include &quot;scribblearea.h&quot;</span>

  MainWindow<span class="operator">::</span>MainWindow()
  {
      scribbleArea <span class="operator">=</span> <span class="keyword">new</span> ScribbleArea;
      setCentralWidget(scribbleArea);

      createActions();
      createMenus();

      setWindowTitle(tr(<span class="string">&quot;Finger Paint&quot;</span>));
      resize(<span class="number">500</span><span class="operator">,</span> <span class="number">500</span>);
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>closeEvent(<span class="type"><a href="../qtgui/qcloseevent.html">QCloseEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="keyword">if</span> (maybeSave()) {
          event<span class="operator">-</span><span class="operator">&gt;</span>accept();
      } <span class="keyword">else</span> {
          event<span class="operator">-</span><span class="operator">&gt;</span>ignore();
      }
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>open()
  {
      <span class="keyword">if</span> (maybeSave()) {
          <span class="type"><a href="../qtcore/qstring.html">QString</a></span> fileName <span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>getOpenFileName(<span class="keyword">this</span><span class="operator">,</span>
                                     tr(<span class="string">&quot;Open File&quot;</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>currentPath());
          <span class="keyword">if</span> (<span class="operator">!</span>fileName<span class="operator">.</span>isEmpty())
              scribbleArea<span class="operator">-</span><span class="operator">&gt;</span>openImage(fileName);
      }
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>save()
  {
      <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>action <span class="operator">=</span> qobject_cast<span class="operator">&lt;</span><span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span><span class="operator">&gt;</span>(sender());
      <span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span> fileFormat <span class="operator">=</span> action<span class="operator">-</span><span class="operator">&gt;</span>data()<span class="operator">.</span>toByteArray();
      saveFile(fileFormat);
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>about()
  {
      <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>about(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">&quot;About Scribble&quot;</span>)<span class="operator">,</span>
              tr(<span class="string">&quot;&lt;p&gt;The &lt;b&gt;Scribble&lt;/b&gt; example shows how to use QMainWindow as the &quot;</span>
                 <span class="string">&quot;base widget for an application, and how to reimplement some of &quot;</span>
                 <span class="string">&quot;QWidget's event handlers to receive the events generated for &quot;</span>
                 <span class="string">&quot;the application's widgets:&lt;/p&gt;&lt;p&gt; We reimplement the mouse event &quot;</span>
                 <span class="string">&quot;handlers to facilitate drawing, the paint event handler to &quot;</span>
                 <span class="string">&quot;update the application and the resize event handler to optimize &quot;</span>
                 <span class="string">&quot;the application's appearance. In addition we reimplement the &quot;</span>
                 <span class="string">&quot;close event handler to intercept the close events before &quot;</span>
                 <span class="string">&quot;terminating the application.&lt;/p&gt;&lt;p&gt; The example also demonstrates &quot;</span>
                 <span class="string">&quot;how to use QPainter to draw an image in real time, as well as &quot;</span>
                 <span class="string">&quot;to repaint widgets.&lt;/p&gt;&quot;</span>));
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>createActions()
  {
      openAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;&amp;Open...&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      openAct<span class="operator">-</span><span class="operator">&gt;</span>setShortcut(tr(<span class="string">&quot;Ctrl+O&quot;</span>));
      connect(openAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(open()));

      foreach (<span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span> format<span class="operator">,</span> <span class="type"><a href="../qtgui/qimagewriter.html">QImageWriter</a></span><span class="operator">::</span>supportedImageFormats()) {
          <span class="type"><a href="../qtcore/qstring.html">QString</a></span> text <span class="operator">=</span> tr(<span class="string">&quot;%1...&quot;</span>)<span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>(format)<span class="operator">.</span>toUpper());

          <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>action <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(text<span class="operator">,</span> <span class="keyword">this</span>);
          action<span class="operator">-</span><span class="operator">&gt;</span>setData(format);
          connect(action<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(save()));
          saveAsActs<span class="operator">.</span>append(action);
      }

      printAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;&amp;Print...&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      connect(printAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> scribbleArea<span class="operator">,</span> SLOT(print()));

      exitAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;E&amp;xit&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      exitAct<span class="operator">-</span><span class="operator">&gt;</span>setShortcut(tr(<span class="string">&quot;Ctrl+Q&quot;</span>));
      connect(exitAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(close()));

      clearScreenAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;&amp;Clear Screen&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      clearScreenAct<span class="operator">-</span><span class="operator">&gt;</span>setShortcut(tr(<span class="string">&quot;Ctrl+L&quot;</span>));
      connect(clearScreenAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span>
              scribbleArea<span class="operator">,</span> SLOT(clearImage()));

      aboutAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;&amp;About&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      connect(aboutAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(about()));

      aboutQtAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;About &amp;Qt&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      connect(aboutQtAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <a href="qapplication.html#qApp">qApp</a><span class="operator">,</span> SLOT(aboutQt()));
  }

  <span class="type">void</span> MainWindow<span class="operator">::</span>createMenus()
  {
      saveAsMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">&quot;&amp;Save As&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      foreach (<span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>action<span class="operator">,</span> saveAsActs)
          saveAsMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(action);

      fileMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">&quot;&amp;File&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(openAct);
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addMenu(saveAsMenu);
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(printAct);
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addSeparator();
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(exitAct);

      optionMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">&quot;&amp;Options&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      optionMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(clearScreenAct);

      helpMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">&quot;&amp;Help&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      helpMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(aboutAct);
      helpMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(aboutQtAct);

      menuBar()<span class="operator">-</span><span class="operator">&gt;</span>addMenu(fileMenu);
      menuBar()<span class="operator">-</span><span class="operator">&gt;</span>addMenu(optionMenu);
      menuBar()<span class="operator">-</span><span class="operator">&gt;</span>addMenu(helpMenu);
  }

  bool MainWindow<span class="operator">::</span>maybeSave()
  {
      <span class="keyword">if</span> (scribbleArea<span class="operator">-</span><span class="operator">&gt;</span>isModified()) {
         <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>StandardButton ret;
         ret <span class="operator">=</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>warning(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">&quot;Scribble&quot;</span>)<span class="operator">,</span>
                            tr(<span class="string">&quot;The image has been modified.\n&quot;</span>
                               <span class="string">&quot;Do you want to save your changes?&quot;</span>)<span class="operator">,</span>
                            <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Save <span class="operator">|</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Discard
                            <span class="operator">|</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Cancel);
          <span class="keyword">if</span> (ret <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Save) {
              <span class="keyword">return</span> saveFile(<span class="string">&quot;png&quot;</span>);
          } <span class="keyword">else</span> <span class="keyword">if</span> (ret <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Cancel) {
              <span class="keyword">return</span> <span class="keyword">false</span>;
          }
      }
      <span class="keyword">return</span> <span class="keyword">true</span>;
  }

  bool MainWindow<span class="operator">::</span>saveFile(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span> <span class="operator">&amp;</span>fileFormat)
  {
      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> initialPath <span class="operator">=</span> <span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>currentPath() <span class="operator">+</span> <span class="string">&quot;/untitled.&quot;</span> <span class="operator">+</span> fileFormat;

      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> fileName <span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>getSaveFileName(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">&quot;Save As&quot;</span>)<span class="operator">,</span>
                                 initialPath<span class="operator">,</span>
                                 tr(<span class="string">&quot;%1 Files (*.%2);;All Files (*)&quot;</span>)
                                 <span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">::</span>fromLatin1(fileFormat<span class="operator">.</span>toUpper()))
                                 <span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">::</span>fromLatin1(fileFormat)));
      <span class="keyword">if</span> (fileName<span class="operator">.</span>isEmpty()) {
          <span class="keyword">return</span> <span class="keyword">false</span>;
      } <span class="keyword">else</span> {
          <span class="keyword">return</span> scribbleArea<span class="operator">-</span><span class="operator">&gt;</span>saveImage(fileName<span class="operator">,</span> fileFormat<span class="operator">.</span>constData());
      }
  }

</pre>
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<!-- @@@touch/fingerpaint/mainwindow.cpp -->
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